In 2007, CNES and the dynamic meteorology laboratory (LMD - Laboratoire de Météorologie Dynamique) validated the concept of aeroclippers during the VASCO experiment (Validation of the Aeroclipper Systen under Convective Occurrences). During the experiment, two balloons observed the cyclone DORA... from the inside!
The aeroclipper is an original observation system composed of a balloon flying some tens of metres above the ocean and stabilized by a partly immersed guide-rope.
This guide-rope is linked to:
- a flying atmospheric instrument gondola for measuring the meteorological parameters (pressure, temperature, relative humidity, relative wind speed)
- a under water oceanic instrument gondola for measuring the sea surface temperature and the sea surface salinity.
The guide-rope mass deposited on the ocean surface keeps the wind-propelled aeroclipper at very low altitude.
Developed in cooperation by CNES and the LMD, the aeroclipper was designed to perform long-length course at very low altitude above tropical oceans, and to measure during its course the heat, water vapour and movement exchanges between the ocean and the atmosphere, as well as their reinforcement when close to a storm system.
Two balloons in the eye of a cyclone
Those observations were capital because in the Tropics, the ocean plays a primordial role on the weather patterns and the climate through the ocean-atmosphere exchanges.
The reason for using such balloons for this type of measurements is that those ocean-atmosphere exchanges are very difficult to measure at bigger scale by other means such as satellites.
During the VASCO experiment, in January 2007, six aeroclippers were launched above the Tropical Indian Ocean from Seychelles.
Besides the results on the intensification of the ocean-atmosphere exchanges when closer to a storm system, two aeroclippers entered in the inside of the Tropical cyclone Dora with wind speed greater than 45ms-1 (160km/h) and stayed a few days in the eye of the cyclone.
It was the world-first demonstration of the aeroclippers' capacity to enter inside the cyclones. This opens very promising pathways toward a better knowledge and a better forecasting capability of those devastating phenomena.
J.P. Duvel1, C. Basdevant1, H. Bellenger1, G. Reverdin2, A. Vargas3 and J. Vialard2The aeroclipper: a new device to explore convective systems and cyclones
1 Laboratoire de Météorologie Dynamique (LMD), CNRS, UPMC, ENS, Ecole Polytechnique, Paris, France
2 Laboratoire d'Océanographie Expérimentation et Approches Numériques (LOCEAN), CNRS, UPMC, IRD, Paris,
3 Centre National d’Etudes Spatiales (CNES), Toulouse, France